There was some question on another topic regarding speakers about trunk divider use. The topic was correctly moved to the modified/custom forum. I am posting this info here as it applies to originality.
Divider boards were only used in 55. Painted light gray with Jacking instructions applied about center, usually a little crooked. As Paul stated, 56 to mid 56 used a black rubber curtain. Mid 56 and 57 used a burtex curtain.
Original trunk divider boards
Moderator: Joe Johnston